Friday, 29 September 2017

Transport for London (TFL), the local government body responsible for transport in London, which also runs the London Underground (known as Tubes) has been using smartphone Wi-Fi data to work out how people travel on the stations.

They did the trial and collected data in 2016 and have also openly talked about it (see this talk for example), they have now published their findings which is available here. One of the interesting findings for example is that 18 different routes taken by customers between King's Cross St Pancras and Waterloo - and many people don't use the shortest route changing Tube lines

Its interesting to think that because many people do not have their Wi-Fi switched on while outside and many others who put their phone in plane more while in the underground (no mobile coverage, in case you are wondering), this data is probably not as detailed as it could have been.

Nevertheless, there is a talk of bringing Mobile connectivity into the underground network. Once its there, the combination of data could be far more valuable.

Sunday, 11 June 2017

The CEO of UK mobile network operator EE recently announced on twitter that they have achieved 429 Mbps in live network. The following is from their press release:

EE, the UK’s largest mobile network operator and part of the BT Group, has switched on the next generation of its 4G+ network and demonstrated live download speeds of 429Mbps in Cardiff city centre using Sony’s Xperia XZ Premium, which launched on Friday 2 June.

The state of the art network capability has been switched on in Cardiff and the Tech City area of London today. Birmingham, Manchester and Edinburgh city centres will have sites upgraded during 2017, and the capability will be built across central London. Peak speeds can be above 400Mbps with the right device, and customers connected to these sites should be able to consistently experience speeds above 50Mbps.

Sony’s Xperia XZ Premium is the UK’s first ‘Cat 16’ smartphone optimised for the EE network, and EE is the only mobile network upgrading its sites to be able to support the new device’s unique upload and download capabilities. All devices on the EE network will benefit from the additional capacity and technology that EE is building into its network.

...

The sites that are capable of delivering these maximum speeds are equipped with 30MHz of 1800MHz spectrum, and 35MHz of 2.6GHz spectrum. The 1800MHz carriers are delivered using 4x4 MIMO, which sends and receives four signals instead of just two, making the spectrum up to twice as efficient. The sites also broadcast 4G using 256QAM, or Quadrature Amplitude Modulation, which increases the efficiency of the spectrum.

If you read the press release carefully, EE are now using 65MHz of spectrum for 4G. I wanted to provide a calculation for whats possible in theory with this much bandwidth.

Going back to basics (detailed calculation for basics in slideshare below), in LTE/LTE-A, the maximum bandwidth possible is 20MHz. Any more bandwidth can be used with Carrier Aggregation. So as per the EE announcement, its 20 + 10 MHz in 1800 band and 20 + 15 MHz in 2600 band

So for 1800 MHz band:

50 resource blocks (RBs) per 10MHZ, 150 for 30MHz.
Each RB has 12x7x2=168 symbols per millisecond in case of normal modulation support cyclic prefix (CP).
For 150 RBs, 150 x 168 = 25200 symbols per ms or 25,200,000 symbols per second. This can also be written as 25.2 Msps (Mega symbols per second)
256 QAM means 8 bits per symbol. So the calculation changes to 25.2 x 8 = 201.6 Mbps. Using 4 x 4 MIMO, 201.6 x 4 = 806.4Mbps
Removing 25% overhead which is used for signalling, this gives 604.80 Mbps

Repeating the same exercise for 35MHz of 2600 MHz band, with 2x2 MIMO and 256 QAM:

Saturday, 8 April 2017

Brits love their red phone boxes. Even with mobiles prevalent today, we don't want to get rid of the phone boxes. The BBC estimates that there are 46,000 phones boxes in use today, including 8,000 red ones.

Two British Phonebox enthusiasts, Prof. Nigel Linge and Prof. Andy Sutton have written a very well researched and comprehensive book on this topic looking at the history and evolution of the humble phone boxes through all of its major models, including those that were introduced by organisations such as the emergency services. The British Phonebox is available to purchase from Amazon and other popular bookshops.

In addition to the book, they have also written an article in 'The Journal' that gives a taster of whats in the book. Its available to download here.

5 interesting facts from the little reading that I did on this topic:

The model K1 (K stand for Kiosk) was very unpopular and hence a competition was held to find the best possible design. The winning design by Sir Giles Gilbert Scott became K2 that was rolled out in 1926

Sir Giles had suggested silver colour with blue and green interior. This was changed to red for making it easy to spot

The most popular and loved model is the K6 that was designed to celebrate King George V’s Silver Jubilee, though he died before any of them were actually installed.

Before Queen Elizabeth came along, a vague representation of the Tudor crown was used on the telephone boxes. Wanting to put her stamp on things after she ascended to the throne in 1952, QEII had all of the crowns changed to St. Edward's Crown, the crown actually used in coronations. Scotland opted to keep the Crown of Scotland on theirs, and so all K6 boxes manufactured after 1955 had to be made with a slot in the top to insert the plate with the correct crown depending on the location of the booth.

Sunday, 19 March 2017

In an earlier post I mentioned that there will be three different types of spectrum that would be needed for 5G; coverage layer, capacity layer and high throughput layer. There is now a consensus within the industry for this approach.

In a 5G seminar, back in Jan, there were a few speakers who felt that there is an informal agreement about the frequencies that will be used. One such slide from Ofcom could be seen in the picture above. Ofcom has also recently released a report expanding on this further.

Analysys Mason has nicely summarized the bands suggested by Ofcom and possibly available in the UK for 5G in the picture above.

Global mobile Suppliers Association (GSA) has also nicely summarised the bands under investigations and trials as follows:

Finally, as a reminder, list of bands originally approved for IMT-2020 (5G) as follows:

Another potential band, not being mentioned above is the 66-76GHz spectrum. This band is adjacent to the 60 GHz Wi-Fi (57 GHz - 66 GHz). Lessons learned from that band can be applied to the 5G band too.

Friday, 24 February 2017

This week EE has finally done a press release on what they term as Airmasts (see my blog post here). Back in Nov. last year, Mansoor Hanif, Director of Converged Networks and Innovation BT/EE gave an excellent presentation on connecting rural Scottish Islands using Airmasts and Droneways at the Facebook TIP Summit. Embedded below are the slides and video from that talk.

It is designed to beam LTE coverage from the sky to customers on the ground during disasters or big events....Here’s how it works. The drone we tested carries a small cell and antennas. It’s connected to the ground by a thin tether. The tether between the drone and the ground provides a highly secure data connection via fiber and supplies power to the Flying COW, which allows for unlimited flight time. The Flying COW then uses satellite to transport texts, calls, and data. The Flying COW can operate in extremely remote areas and where wired or wireless infrastructure is not immediately available. Like any drone that we deploy, pilots will monitor and operate the device during use.Once airborne, the Flying COW provides LTE coverage from the sky to a designated area on the ground. Compared to a traditional COW, in certain circumstances, a Flying COW can be easier to deploy due to its small size. We expect it to provide coverage to a larger footprint because it can potentially fly at altitudes over 300 feet— about 500% higher than a traditional COW mast. Once operational, the Flying COW could eventually provide coverage to an area up to 40 square miles—about the size of a 100 football fields. We may also deploy multiple Flying COWs to expand the coverage footprint.

Nokia's Ultra Compact Network provides a standalone LTE network to quickly re-establish connectivity to various mission-critical applications including video-equipped drones. Drones can stream video and other sensor data in real time from the disaster site to a control center, providing inputs such as exact locations where people are stranded and nature of the difficulty of reaching the locations.

Friday, 1 July 2016

Many of my readers would be aware that UK is probably the first country to have decided to move its emergency services network from an existing TETRA network to a commercial LTE network operated by EE.

While some people have hailed this as a very bold move in the right direction, there is no shortage of critics. Around 300,000 emergency services users will share the same infrastructure used by over 30 million general users.

Steve Whatson, deputy director Delivery, Emergency Services Mobile Communications Programme (ESMCP) – the organisation within the UK Home Office procuring ESN – assured delegates that ESN will match the existing dedicated Airwave emergency services communication network in terms of coverage for roads, outdoor hand portable devices and marine coverage. Air to ground (A2G) will extend its reach from 6,000ft to 12,000ft.Whatson also pointed out that coverage is not one single piece, but will comprise a number of different elements, which all need to mesh into one seamless network run by the ESN Lot 3 Mobile Services (main 4G network) provider – EE.This includes: EE’s main commercial 4G network; Extended Area Services (hard-to-reach areas of the UK where new passive sites are to be built under a separate contract and then equipped with EE base stations); air-to-ground; London Underground; Crossrail; marine coverage (to 12 nautical miles); and special coverage solutions.EE is currently rolling out new 4G sites – it will eventually have some 19,500 sites – and is upgrading others with 800MHz spectrum, which propagates over longer distances and is better at penetrating buildings than its other 4G spectrum holdings. Crucially for ESN, it is also switching on a Voice over LTE (VoLTE) capability, starting with the UK’s main cities....Mission critical networks must be always available and have levels of resilience far in excess of commercial networks. Speaking exclusively to Wireless in early May, Tom Bennett, group director Technology Services, Architecture & Devices at EE, said: ‘We already achieve a very high availability level, but what the Home Office was asking for effectively was about a 0.3% increase against our existing commercial availability levels.‘Now for every 0.1% increase in availability there is a significant investment because you are at the extreme top end of the curve where it is harder and harder to make a noticeable difference.’There are very specific requirements for coverage and availability of the ESN network for the UK road system. Bennett says: ‘Mobile is based on a probability of service. No more than 1% of any constabulary’s roads are allowed to be below 75% availability, and on major roads it is 96% availability. A coverage gap in this context is no more than 1km.’The current Airwave network has approximately 4,000 sites, many with back-up generators on site with fuel for seven days of autonomous running if the main power is cut, along with a range of resilient backhaul solutions.Bennett says that out of EE’s 18,500 sites it has about the same number of unique coverage sites (ie. no overlapping coverage) – around 4,000. ‘As part of our investment programme, those unique coverage sites will need a significant investment in the causes of unavailability – ie. resilient backhaul and back-up batteries.’He explains that EE has undertaken a lot of analysis of what causes outages on its network, and it has combined that data with the Home Office’s data on where the natural disasters in the UK have occurred over the past 10 years.From this, EE is able to make a reasonable assessment of which sites are likely to be out of action due to flooding or other disasters for more than three or four days. ‘For those sites – and it is less than 4,000 – you need generators too, because you may not be able to physically access the sites for some days,’ says Bennett.For obvious reasons, the unique coverage sites are mostly in rural areas. But as Bennett points out, the majority of cases where the emergency services are involved is where people are – suburban and urban areas.‘In these areas EE has overlapping coverage from multiple sites to meet the capacity requirements, so if a site goes down, in the majority of cases we have compensation coverage. A device can often see up to five tower sites in London, for example,’ he says.Having adequate backhaul capacity – and resilient backhaul at that – is vital in any network. Bennett says EE is installing extra backhaul, largely microwave and fibre, but other solutions will also be used including satellite and LTE relay from base station to base station – daisy chaining. On 9 May 2016, EE announced a deal with satellite provider Avanti to provide satellite backhaul in some areas of the UK.Additional coverage and resilience will be offered by RRVs (rapid response vehicles), which EE already has in its commercial network today, for example, to provide extra capacity in Ascot during the racing season.‘We would use similar, although not exactly the same technology for disaster recovery and site/service recovery, but with all the backhaul solutions,’ says Bennett. ‘Let’s say we planned some maintenance or upgrade work that involved taking the base station out for a while.‘We’d talk to the chief inspector before the work commences. If he says, there’s no chance of doing that tonight, we can put the RRV there, and provided we maintain coverage, we can carry out the work. RRVs are a very good tool for doing a lot of things.’At the British APCO event, Mansoor Hanif, director of Radio Access Networks at EE said it was looking at the possibility of using ‘airmasts’ to provide additional coverage. Meshed small cells, network in a box and repeater solutions are becoming available for these ‘airmasts’, which will provide coverage from balloons, or UAVs – tethered drones with power cables and optical fibre connected to them.

Mansoor Hanif, Director of RAN at EE gave a presentation on this at Critical Communications World 2016 and has also given an interview. Both are embedded below.

Friday, 17 June 2016

In January 1985 the UK launched its first mobile networks. Now, thirty years on, many people and companies in the UK have been celebrating this enormous achievements and advances that have been made since then and which have seen the mobile evolve from a humble telephone into the multimedia pocket computer which has become such an essential part of modern life. It was simply not possible in 1985 to envisage a country that would be able to boast more active mobile phones than people or to have along the way clocked up several world firsts, and be now leading on the deployment of 4G and shaping the future 5G technologies.

Sunday, 5 July 2015

Over the last few months I heard quite a few talks about Smart Cities. Here are two that I thought its worth posting and a very good TEDx talk at the bottom

I think we all agree that more and more people will move from rural to urban areas and the cities will not only grow in population but also in size. The infrastructure will have to grow to be able to cope with the influx of people and increased demand on services.

I guess in most developed nations we have the 1.0 Era Digital City which is long way away from the 3.0 Era Smart City.

To be a full fledged 3.0 Smart City, every aspect of our life may need to evolve into "Smart". Anyway, here is the complete presentation:

If you want to find out more about the Milton Keynes smart city, also see this video on Youtube. There are driverless pods and other autonomous cars which may be considered as initial step towards smart cities, see this interesting video here.

Finally here is the TEDx talk about designing these smart cities for future:

Saturday, 28 March 2015

Last week at work, we released a report titled "UK Spectrum Usage & Demand". The only time most people hear about spectrum is when there are some auctions going on. Often a small chunk of spectrum gets sold off for billion(s) of dollars/pounds and these surely make a headline. As I recently found out, 50% of spectrum in UK is shared and 25% is license exempt.

Anyway, this first edition of the report focuses on Public Mobile, Utilities, Business Radio and Space/Satellites. Space is becoming an important area of focus here as it is a significant contributor to the UK economy.

Anyway, the report is embedded below and is available to download from here:

@o2 @ronandunneo2 O2 in the USA: £6 per meg. Vodafone in the USA: £25 for 100 meg a day. Sorry, but that's an easy choice.
— Benedict Evans (@BenedictEvans) May 18, 2013

Those who follow me on Twitter may have noticed me ranting about the roaming prices recently so I thought that this is a perfect opportunity to put my thoughts down.

As being discussed above, I went on the websites of two UK operators and found out about their roaming rates to India and The USA and they are as follows:

It should be noted that there is a better rate available with some kind of bundle opt-in from both the operators and I have not shown about the other UK operators but they offer a similar sort of rate so I am not trying to single out O2 and/or Vodafone.

Since LTE is 'All-IP' network my interest is more from Data point of view rather than the voice point of view. A colleague who went to India recently decided that enough is enough and he bought a SIM in India locally. Apparently is just a bit too difficult to get SIM in India if you are not an Indian resident, nevertheless he somehow managed it. The rates as shown below was INR 24 for 100 MB of data.

Rs. 24 is something like $0.50 or £0.35. You see my problem regarding the data rates? People may be quick to point out here that India has the cheapest data rates in the world. On the other hand we look at US, the rates are as follows:

Even if we assume $15 / 1GB data, its far cheaper than the roaming rate which may be something like, £3/MB = £3000/GB or £6/MB = £6000/GB.

I blogged about all the interesting developments that have been happening in LTE World Summit regarding the roaming solutions but what is the point of having all these solutions if the operators cant work out a way to reduce these costs. Or is it that they do not want to reduce these costs as they are a good source of income?

The operators complain that the OTT services are taking business away from them and turning them into dumb data pipes but to a lot of extent its their fault. People like me who travel often dont want to spend loads of cash on data and have worked out a way around it. Most of the places I visit have WiFi, most of my work is not urgent enough and I can wait till I am in a WiFi coverage area. In some parts of the world, still I have to buy an expensive WiFi access but compared to the roaming rates, its still cheap so I have stopped complaining about it. My decision to book a hotel depends of reviews, free breakfast and free WiFi. Some of our clients who give us their phone to use abroad strictly inform us that data should not be turned on unless its a matter of life and death.

If the operators dont change their strategies and work out a better solution for the roaming rates I am afraid that their short term gains will only lead to long term pains.

The last table is from an Ofcom document here. Its very interesting read. For example I didnt know that The L-band was the first major part of Ofcom spectrum awards programme relevant to mobile services. It consists of 40MHz between 1452MHz and 1492MHz. The auction took place in May 2008, in which Qualcomm won the entirety of the available spectrum.

Here is the summary of the operators working on LTE:

Everything Everywhere (EE = Orange + T-Mobile) - They are calling their '4G' service as EE, covering up to 70% of the UK by the end of 2013. Network kit provided by Huawei.

Three - Samsung will provide the Radio Access Network, and the core infrastructure, for Three's LTE (4G) network. That includes the base stations, and radio core. 3 UK has agreed to purchase 2 x 15 MHz of 1800 MHz spectrum from Everything everywhere, and plans commercial launch of LTE service in 2013.

Telefonica (O2) trial network - Equipment supplied by Nokia Siemens Networks (NSN) for both the Radio and Core network elements. Backhaul for the 4G trial network has been provided using Microwave Radio Equipment from Cambridge Broadband Networks Limited, NEC and Nokia Siemens Networks.

Updated 13/09/12 - 11:25

UK Broadband rolled out the first commercial TD-LTE network in London back in February (available to customers since May 2012). The equipment is provided by Huawei. They have 40MHz in Band 42 (3.5GHz) and 84MHz in band 43 (3.6GHz).